CHEMICAL BONDING

Atoms & Ions

An Ion vs an Atom?● A stable atom has equal # of p+& e-.● Losing an e- makes atom POSITIVE.● Gaining an e- makes atom NEGATIVE.

Ex: Na Atom vs Na Ion (cation)

Ex: Cl Atom vs Cl Ion (anion)

What did you notice about the ions?

Losing an e- decreases the size of the atom and gaining e- increases the size of an atom.

Chemical Bonding

● Valence electrons are the electrons involved in bond formation. Consider:

● Ions● Lewis Dot Structure(use valence e-)● Stable Octet (or Duet)

Octet Rule vs Duet Rule

Atoms reacts with other atoms to have stable octet.When atoms react bonds are formed.Octet Rule: Atoms want 8 e- in their valence shell. Duet Rule: Only applies to Hydrogen. Needs two valence e-

Ex: Lewis Dot Structure & Bonds

Ex: Duet Rule

Types of Bonding

Ionic Bonds: Transfer of e-

Between Metal (Cation) & nonmetal(anion)Covalent (Molecular) Bonds:

Share e- Between a nonmetal & a nonmetal(anions)Metallic Bonding:

Between metals

Types of Bonding

Ionic Bonds: NaCl

Which ball is the Na and how did you figure it out?

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Types of Bonding

Covalent Bonding

Metalic Bonding

F−

Review:Viedo

N3− O2− F−

Ionic & Covalent Bond Review

Metallic BondingNa1+ B3+ Mg2+

B3+

How did we get here?

● Count the valence e- for each atom.

● Find the total # of e-● Choose the central atom. ● Carbon always is the

central atom in a structure● Connect other atoms to the

central atom.

Methane: CH4

STOP HERE!!!

Covalent Bonding

● Covalent bonds occurs

between nonmetals

● They share e-

1. Polar Covalent:

Uneven distribution

(share) of e-

2. Non-polar covalent:

even

distribution(share) of

e-

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Ex: Covalent Bonding

● Polar Covalent

● Non-polar

covalent

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Naming Common Ions

Metals(cation): Name stays the same.Ex: Li (Lithium atom) Li+ ( Lithium Ion): Lithium

Nonmetal(anion): Name takes -ide at the end.Ex: Cl (Chlorine atom) Cl- (Chlorine Ion): Chloride ALWAYS WRITE: CATION (METAL) FIRST AND ANION (NONMETAL) SECOND

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Complete the names of the following ions. Ba2+ Al3+ K+

_________ __________ _________

N3− O2− F−

_________ __________ _________

P3− S2− Cl− _________ __________ _________

Learning Check

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Ba2+ Al3+ K+

Barium Aluminum Potassium

N3− O2− F−

Nitride Oxide Fluoride

P3− S2− Cl−

Phosphide Sulfide Chloride

Solution

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Is it Ionic or Covalent? Write the names of the

following compounds. 1) CaO ___________

2) KBr ___________

3) Al2O3 ___________

4) MgCl2___________

Learning Check

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Write the names of the following compounds: All are Ionic

1)CaO calcium oxide2)KBr potassium bromide3)Al2O3 aluminum oxide4)MgCl2 magnesium chloride

Solution

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Learning Check

Write the formulas and names for compounds of the following ions:

Br− S2− N3−

Na+

Al3+

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Solution

Br− S2− N3−

Na+

Al3+

AlNaluminum nitride

Al2S3aluminum sulfide

AlBr3aluminum bromide

Na3Nsodium nitride

Na2Ssodium sulfide

NaBrsodium bromide

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Transition Metals and Ionic Bonds Roman numeral USED FOR TRANSITION

METAL CHARGE. Transition metal CHARGE Will be given.

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Example:

Chromium: Cr3+ Oxygen: O2-

Criss cross charges to write formulaRemember Cr is a transition metal.Cr3+ O2- Cr2O3

Name the compound: Cr2O3: Chromium(III) oxide

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Naming FeCl2To name FeCl21. Determine the charge of the cation from the formula

Fe2+ Cl- Fe ion = 2+2. Cation name stays the same and add Roman numeral in

parentheses to show the cation charge.Fe2+ = iron(II)

3. Write the anion with ide ending. Cl- Chloride 4. Criss cross the charges. Fe2+ Cl1- FeCl2 = iron(II) chloride

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Learning Check

Select the correct name for each.A. Fe2S3

1) iron sulfide 2) iron(II) sulfide 3) iron(III) sulfide

B. Cu2O 1) copper oxide 2) copper(I) oxide 3) copper(II) oxide

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Writing Formulas

Write a formula for potassium sulfide.1. Identify the cation and anion. potassium = K+ sulfide = S2−

2. Balance the charges. K+ S2−

K+

2(1+) + 1(2-) = 0(neutral)

3. 2 K+ and 1 S2− = K2S

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Solution

The correct formula isA. Copper (I) nitride

Cu3N Need 3Cu+ and 1N3-

B. Lead (IV) oxide Pb2O4 = PbO2 Need 1Pb4+ and 2O2-

(It is simplified)

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Learning Check

What is the correct formula for each of the following?

A. Copper(I) nitride 1) CuN 2) CuN3 3) Cu3N

B. Lead(IV) oxide 1) PbO2 2) PbO 3) Pb2O4

Example

CO:

N2Cl4:

Carbonmonoxide

diNitrogentetrachloride

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Guide to Writing Formulas from the Name

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Naming Ionic Compounds with Variable Charge Metals